1. Field of the Invention
Exemplary embodiments of the present invention relate to a method for inspecting a measurement object and, more particularly, to a method for inspecting a measurement object formed on a printed circuit board.
2. Discussion of the Background
In general, electronic appliances include at least one printed circuit board printed circuit board (PCB), and various kinds of electronic devices are mounted on the printed circuit board.
In order to check the credibility of a substrate having electronic devices mounted thereon, inspecting the mounting status of the electronic devices is required and it is important to setting up a region of a measurement object.
Previously, in order to set up the region of a measurement object, a two dimensional image is captured to be used. However, setting up the region of a measurement object from the two dimensional image is not easy since it is hard to discriminate the measurement object from environments because a device is sensitive to a color and an illuminator. When the dimension of the measurement object is changed, it is hard to discriminate the measurement object. Furthermore, when the image contains a noise, for example, when not only the measurement object but also a pattern or a silk screen pattern is formed on a substrate, it is hard to discriminate the measurement object since a noise may be generated by a camera and the region of the measurement object may be confused with a pad region adjacent to the region of the measurement object. Additionally, a device has been extracted by using a fillet portion of a two dimensional image of the device, but when the fillet of the device is small, there is a limitation in extracting the device using the fillet.
Therefore, a new method for inspecting a three-dimensional shape, which is capable of avoid above mentioned problems, is required.